Applying classification algorithms in practice

In this paper we present a perspective on the overall process of developing classifiers for real-world classification problems. Specifically, we identify, categorize and discuss the various problem-specific factors that influence the development process. Illustrative examples are provided to demonstrate the iterative nature of the process of applying classification algorithms in practice. In addition, we present a case study of a large scale classification application using the process framework described, providing an end-to-end example of the iterative nature of the application process. The paper concludes that the process of developing classification applications for operational use involves many factors not normally considered in the typical discussion of classification models and algorithms.     

Detecting Overdispersion in Large Scale Surveys: Application to a Study of Education and Social Class in Britain (with Comments)

A practical problem with large scale survey data is the potential for overdispersion. Overdispersion occurs when the data display more variability than is predicted by the variance–mean relationship for the assumed sampling model. This paper describes a simple strategy for detecting and adjusting for overdispersion in large scale survey data. The method is primarily motivated by data on the relationship between social class and educational attainment obtained from a 2% sample from the 1991 census of the population of Great Britain. Overdispersion can be detected by first grouping the data into a number of strata of approximately equal size. Under the assumption that the observations are independent and there is no variability in the parameter of interest, there is a direct relationship between the nominal standard errors and the empirical or sample standard deviation of the parameter estimates obtained from each of the separate strata. With the 2% sample from the British census data, quite a discernible departure from this relationship was found, indicating overdispersion. After allowing for overdispersion, improved and more realistic measures of precision of the strength of the social class–education associations were obtained.     

基于博弈分析的农村信用社产权改革路径选择

随着我国农村信用社改革的步步深化,新型产权组织模式与运行机制的构建已经走到了攻坚阶段。文章在归纳分析农村信用社改革与发展背景及基本现状的基础上,围绕政府与农村信用社双方的益损值,对政府推行农村信用社合作制规范进行了博弈分析,由最终的纳什均衡分析结果,得出了在现有农村信用社基础上搞统一的合作制规范不切实际,农村信用社改革必须走“多元化”产权组织模式道路的结论,并就新时期如何进一步发展与完善农村信用社“多元化”产权组织模式提出了几点政策性建议。     

Best subset selection of autoregressive models with exogenous variables and generalized autoregressive conditional heteroscedasticity errors

Summary.  We develop an efficient way to select the best subset autoregressive model with exogenous variables and generalized autoregressive conditional heteroscedasticity errors. One main feature of our method is to select important autoregressive and exogenous variables, and at the same time to estimate the unknown parameters. The method proposed uses the stochastic search idea. By adopting Markov chain Monte Carlo techniques, we can identify the best subset model from a large of number of possible choices. A simulation experiment shows that the method is very effective. Misspecification in the mean equation can also be detected by our model selection method. In the application to the stock-market data of seven countries, the lagged 1 US return is found to have a strong influence on the other stock-market returns.     

Variations in Child Care by Grandparents During the First Three Years

Routine child care by grandparents was examined for 1,229 children who were participants in the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care. Four groups were identified: extended full‐time care, extended part‐time care, sporadic care, and no routine care during the first three years. The odds of sporadic child care by grandparents were higher when mothers were relatively young and worked nonstandard hours. The odds of extended full‐time grandparent care versus extended part‐time grandparent care were higher for mothers of color and mothers with more extensive full‐time employment. All types of grandparent care were more likely when a grandparent lived in the household. These findings suggest that grandparent care is heterogeneous and may occur in response to different family circumstances.     

笙馨同音 宗旨如一──略论《文心雕龙》对《文选》的影响

《文心雕龙》书名是刘勰文学观点的集中体现，它强调的是精妙的艺术构思与精美的文学语言的有机结合；而《文选》的选文标准“事出于沉思，义归乎翰藻”，则是萧统文学观点的典型反映。其“沉思”之想与“文心”之思，“翰藻”之文与“雕龙”之采，名异而实同，都体现了他们注重内容与形式相结合的文学观点。《文心》所论文体３４种，《文选》３９种，两书基本相同的文体选目近２０种。其渊源有自，一目了然。     

关于本科生所做毕业设计的思考

提出了理工科院校本科生所做毕业设计的重要性 ,从师生互动、课题选择、经费支持等方面分析了造成本科生毕业设计质量差的主要原因 ,并提出了相应的解决方案。     

苏颂与"三舍人议案"评析

宋代熙宁"三舍人议案"是一个震动朝野、风闻天下,影响至今的重大历史事件.苏颂坚持法制,违抗皇命的大无畏精神值得称赞;"三舍人议案"中关于选才用人的争论有许多经验应该总结,其对现在的干部提拔任用将有所裨益;<宋史>说苏颂"明哲保身","务循故事"也值得商榷.     

Computational Comparison Studies of Quadratic Assignment Like Formulations for the In Silico Sequence Selection Problem in De Novo Protein Design

In this paper an O(n²) mathematical formulation for in silico sequence selection in de novo protein design proposed by Klepeis et al. (2003, 2004), in which the number of additional variables and linear constraints scales with the square of the number of binary variables, is compared to three O(n) formulations. It is found that the O(n²) formulation is superior to the O(n) formulations on most sequence search spaces. The superiority of the O(n²) formulation is due to the reformulation linearization techniques (RLTs), since the O(n²) formulation without RLTs is found to be computationally less efficient than the O(n) formulations. In addition, new algorithmic enhancing components of RLTs with inequality constraints, triangle inequalities, and Dead-End Elimination (DEE) type preprocessing are added to the O(n²) formulation. The current best O(n²) formulation, which is the original formulation from Klepeis et al. (2003, 2004) plus DEE type preprocessing, is proposed for in silico sequence search. For a test problem with a search space of 3.4×10⁴⁵ sequences, this new improved model is able to reduce the required CPU time by 67%.     

自然主义:现实主义到现代主义的中介

本文首先论述了自然主义文学理论产生的原由及自然主义理论比之以往文学的创新之处。其次,阐明自然主义文学以实证的手法、客观的态度,从生物学的角度写人的兽性,打破了以往的写作“禁区”,把不登大雅之堂的东西展现给读者,为现代主义作家描写“异化”现象作了铺垫。再次,自然主义客观真实的环境描写,表现了囿于各种环境中人的生物状态,及与浪漫主义、现实主义的环境描写实质上的不同,以及对现代主义的影响。